A communication system is known in which a communication terminal downloads and obtains various types of data from another communication node that is connected via a network. For example, a technology has become popular in which a browser application (hereinafter, referred to as “browser”) of a communication terminal makes use of the HTTP (which stands for HyperText Transfer Protocol) in order to access HTML files (HTML stands for HyperText Markup Language) that are stored in a Web server on the Internet and in order to download contents from the Web server according to the description in the files. Herein, contents data points to, for example, image data that is used screen formation. Generally, it is often the case that a plurality of sets of contents data is requested from a single HTML file.
Another technology is also widely known in which a proxy server is installed in between an HTTP client (communication terminal) and a Web server; the contents data that is held by the Web server and that is requested from an HTML file is stored in advance in the proxy server; and the HTTP client accesses not the Web server but the proxy server in practice.
When a request for obtaining contents data is received from an HTTP client; the proxy server accordingly obtains the contents data from a Web server. At that time, if additional contents data is required, the proxy server also obtains the additional contents data from the Web server. Once all contents data required to, for example, display a single screen is obtained, the proxy server sends the contents data to the communication terminal serving as the HTTP client.
In the communication terminal, while a screen corresponding to a particular HTML file is being viewed, if a screen corresponding to another HTML file is to be displayed, then it becomes necessary to obtain the contents data required in that screen which is to be displayed. In such a case, there has been a demand that, during the period in which the required contents data is obtained and the display is changed, a central processing unit (CPU) of the communication apparatus must be able to be switched into a sleep mode.
Meanwhile, by using a proxy server as mentioned above, it becomes possible to shorten the time taken to obtain the contents data. That opens up the possibility of reducing the power consumption of the communication apparatus. However, in such a case, it is necessary to install proxy servers at various locations, thereby causing an increase in the cost.